Hi Mandi!
That is awesome to have friends that will visit while you are staying in the "Magic" of Walt Disney World Resort!
Yes, your friends will be able to come and spend time with you and your family, at your resort. When they arrive at the security gates, they will probably be asked to provide a Photo ID, along with information about you (i.e. last name, room number, etc.).
Your friends will also be able to enjoy
Mickey's Backyard BBQ without theme park tickets, because it is located at
The Campsites at Disney's Fort Wilderness Resort. In this case, no tickets are required; just the cost of the dinner show.
Be sure to make your Advanced Dining Reservations and have a magical time!
Raquel